Since the card is now also your residence permit, it's a bad idea to hand it over. As I understand it, the work permit can be cancelled, the residence permit runs until the due date (part of the deal of us paying for it). If they get really shitty and try to cancel residence, you still have 3 months grace. The source for this is an HR person and a lawyer.

Update; a colleague of mine gave up her work permit card and when she went to fly out, airport customs wanted to fine her for being here illegally. A scan of the card had to be faxed to customs B4 they let her get on the airplane.

Since the card is now also your residence permit, it's a bad idea to hand it over. As I understand it, the work permit can be cancelled, the residence permit runs until the due date (part of the deal of us paying for it). If they get really shitty and try to cancel residence, you still have 3 months grace. The source for this is an HR person and a lawyer.

Due to more and more stringent rules being placed on native speakers teaching Englsh by the powers that be it is becoming more and more difficult for native speaking EFL teachers to get a work permit and legally teach in Turkey . Pretty soon Turkish EFL teachers will be the only ones teaching English in Turkey.